The present invention relates to a compressor which compresses fluids such as refrigerants or air and discharges the compressed fluids.
Conventionally, for example, a refrigerator has employed a system of compressing a refrigerant by using a compressor and circulating the compressed refrigerant in a circuit. As such compressor systems in this case, there are available a rotary compressor called a rotary type compressor (e.g., see Japanese Patent Application Laid-Open No. 5-99172 (Patent Document 1)), a scroll compressor, a screw compressor and the like.
The rotary compressor has advantages that a structure is relatively simple and production costs are low, but there is a problem of increases in vibration and torque fluctuation. In the scroll compressor or the screw compressor, there is a problem of high costs caused by bad workability while torque fluctuation is small.
Thus, as described in PCT No. 2003-532008 (Patent Document 2), there has been developed a system which disposes a swash plate as a rotary compression member in a cylinder and partitions compression spaces constituted below and above the swash plate by a vane to compress fluids. According to the compressor of this system, there is an advantage of constituting a compressor which is relatively simple in structure and small in vibration.
However, in the case of the structure of Patent Document 2 described above, since a high pressure chamber and a low pressure chamber are adjacent to each other below and above the compression member (swash plate) in the entire region of the cylinder, a difference between high and low pressures is enlarged, and refrigerant leakage causes a problem of efficiency deterioration.
Moreover, as to the cylinder and the compression member rotating in the cylinder, the same materials are subjected to similar treatments for use, and the cylinder and the member have an equal hardness. Therefore, there have occurred problems that they are easily worn by friction accompanying rotation, and durability of the compression member degrades.
Moreover, the compressor having the structure described in Patent Document 2 described above does not have a so-called non-lubricated specification in which oil such as lubricant is not used.